Mobile irrigation sprinkler apparatuses and processes of operation thereof

ABSTRACT

Tow type irrigation apparatuses and processes operating without anchors wherein the moving pipe train is automatically maintained in a straight line along one portion thereof and along another portion parallel thereto and longitudinally and laterally displaced therefrom while a third intermediate portion between is in a stable inverse curve form.

United States Patent 1 Wagner [45] Apr. 24, 19 73 l l MOBILE IRRIGATIONSPRINKLER 3,360,200 12/1967 Purtell ..239/213 APPARATUSES AND PROCESSESOF OPERATION THEREOF FOREIGN PATENTS OR APPLICATIONS 7' Inventor: MiltonH Wagner, Rt. 256,l47 5/l964 Australia ..239/2l3 Brownfield, Tex. 79316a Primary Examiner-Allen N. Knowles [22] filed: July 1971 AssistantExuminerGcne A. Church [21] Appl. No.: 163,742 Attorney-Ely Silverman 52us. CI. ..239/2l2 [57] ABSTRACT [51] Int. Cl. ..A0lg 25/02 Tow typeirrigation apparatuses and processes operat- [58] Field of Search..239/2l2, 213 ing without anchors wherein the moving pipe train isautomatically maintained in a straight line along one References Ciedportion thereof and along another portion parallel UNITED STATES PATENTSthereto and longitudinally and laterally displaced therefrom while athird intermediate portion between 3,512,548 5/l970 Miller ..239/2l3 Xis in a stable inverse curve form. 2,889,948 6/l959 Leuenberger.........239/2l2 X 3,245,595 4/l966 Purtell ..239/2l2 8 Claims, 21 DrawingFigures [07' 24 3s 35 3 34 wit L iiv'llfllli'li 74 igrant; 20. 2; 204'Patented April 24, 1973 '7 Sheets-Sheet 1 a m v .I no. we no. L N v9 n91 m 11 I. ill I I f I W Lo. Q. 92 i b m Q F #9 v9 2 3V I .l .@9 mo .l.I/ ll m m Nb A I o l. l.. mo. 1 8 i X m9 8 a a N I t l I vb Mvmm mom Vom W wow mom m wow vmm mom Low Q m; w wow N m mm Rum v l NON w n \l vm a4.

mm a 3 A/g LTON H. WAGNER ATTORNFV' Patented April 24, 1973 7Sheets-Sheet 2 INVENTOR: MILTON H. WAGNER Patented April 24, 1973 7Sheets-Sheet 4 no 35 34 33 I32 35 22 LC]: l i I25 a. A. c

7 L 5 93 QT: cl: f T T/ :25, UL g CL :L g

I27 F/G8 32 J T T T "f 3' =L .i, .4: A .4,

6 F/G9 33 L? T T T T I25 W '41 A: A, 5 3| 126 e l F/G/O v LT" f T TI251? Q i: A: .i, 3433 I26 P! F/Gl/ 93 64 42 4| 4o 59 58 J? T 57 [I25 TT "T fi= WE I26 as 3 1 g 35 34 33 IA 93 [2A INVENTOK MILTON H. WAGNER HBBY AT TORNFY Patented April 24, 1973 3,729,140

7 Sheets-Sheet 5 INVENTOR.

MILTON H. WAGNER ATTORNEY Patented April 24, 1973 3,729,140

'7 Sheets-Sheet t FIG. /2 FIG/3 INVENTOR.

A21 4 LTON H. WA GNER AT TORNEY Patented April 24, 1973 '7 Sheets-SheetVOm mom INVENTOR. M/LTU/V H. WAG/V51 ATTORNEY MOBILE IRRIGATIONSPRINKLER APPARATUSES AND PROCESSES OF OPERATION THEREOF CROSS REFERENCETO RELATED APPLICATIONS This in an improvement over my co-pending patentapplication Ser. No. 4,632 filed Jan. 21, 1970 now US. Pat. No.3,640,462 issued Feb. 8, 1972.

BACKGROUND OF THE INVENTION 1. Field of the Invention The field of artto which this invention pertains is procedures for fluid sprinkling orspraying by maneuver and also, apparatus comprising a series of joinedfluid conductors with appropriate spray outlet means and a vehiculartype support means secured thereto, the whole being such to conform tothe contour'of the terrain while being moved from area to area and whilein spraying position.

2. Description of the Prior Art Rotary moving irrigation systems (as inU. S. Pat. Nos. 3,394,739 and 2,604,359) and travelling irrigationsystems that move transversely of the length of the pipe (as in U. S.Pat. No. 3,245,595) apply traction to the wheels thereof that arelocated in and engage wet land and, in moving thereover, damage thecrops therebelow. The transversely moving types also have difficulty inmaintaining alignment of the pipe in a straight line whereby to provideuniform distribution of irrigating water and the corrective actionprovided therein usually lags the obnoxious deviations. The circulartravelling elements cover only about 1rd2/4 of a square field of side oflength d, hence cover only about 78.5 percent of the area withuniformity. Tow type apparatuses as in U. S. Pat. No. 3,295,548 requireanchors and the labor for such heavy work of placement is expensive,where available. This invention solves such problems by applying wheeltraction to dry land and avoiding damaging contact with row crops anddoes not require the placement and/or removal and/or movement of anchorswhileusing a reliable yet inexpensive structure that utilizes thecommonly available farm tractor and inter section service road,

and permits compensation for short periods of varying wind velocity anddirection.

SUMMARY OF THE INVENTION A tractor is maneuvered to force a bend in amoving wheeled pipe train while the pipe train wheels bite into orengage the ground along the area of its straight line movement andS-curved motion to hold the relative pipe position earlier impressedthereupon by movement of a tow tractor. In the continued phase of itsoperation the pipe train to a degree is treated as a nonrigid flexibleelement able to transmit force only parallel to the direction of thelongitudinal axis thereof yet, as the pipe is firmly clamped to some ofeach ofa series of wheel support backets and the pipe train wheelslocated to allow free rotation of each wheel, the curve earlierimpressed on the curved segments of the pipe train is maintained whileother portions of the train travel in laterally spaced apart straightpaths;

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a pictorial representationof the wheeled pipe train assembly portion 24 of apparatus 21 during astage of its operation shown in FIG. 11 as seen along plane 1A-1Athereof.

FIGS. 2 and 3 diagrammatically show, in the overall, the position ofapparatus 21 in the basic sequence of steps providing, on repetition,the full cycle of operation in field 90 shown in FIG. 14. FIG. 2diagrammatically shows the relative positions of parts of apparatus 21in one set of two separate stages of one step of operation; FIG. 3 showsanother, subsequent, set of stages in the subsequent step in the cycleof operation shown in FIG. 14.

FIGS. 4 and 5 show, in the overall, the positions of another apparatus27 in the basic sequence of steps providing; on repetition, the fullcycle of operation shown in FIG. 14', FIG. 4 shows the relative positionof parts of apparatus 21 in one set of two separate stages of one stepof operation; FIG. 5 shows another, subsequent, set of stages in thesubsequent step in the cycle of operation shown in FIG. 14. FIGS. 4 and5 thus show the array of parts of the embodiment of apparatus 27 inpositions corresponding to positions shown in FIGS. 2 and 3 forembodiment 21.

FIG. 6 is a diagrammatic top or plan view of the position of parts ofapparatus 21 in zone 6A of FIG. 2.

Each of FIGS. 7, 8, 9, l0 and 11 is a diagrammatic top view of theposition of parts of apparatus 21 initially in zone 6A through 11B ofFIG. 2; FIGS. 6, 7, 8, 9, 10 and 11 show, respectively, sequentialpositions in the process of movement of apparatus 21 from the positionshown at position of apparatus 21 in FIG. 2 to the position 11 l ofapparatus 21 in FIG. 2.

FIGS. 68, 7A, 8B, 8C and 9B are enlarged diagrammatic views in the zone11B of FIGS. 2, 6, 7, 8, 9, 10 and 11 during motion of apparatus 21 fromthe position 1 10 thereof shown in FIG. 2 to the position 11 1 thereofshown in FIG. 2. Zone corresponding to 11B in FIG. 2 is shown as zonellBB in FIG. 4. FIGS. 6B, 7A, 7B, 8B and 9B are drawn to a larger scalethan FIGS 6 11.

FIG. 6B diagrammatically illustrates geometric relations of direction oftractor path, direction of path of wheels of wheeled units 31 and 32 andshape of pipe portions 50 and 51 in a position and stage of operationintermediate between those positions and stages shown in FIGS. 6 and 7to a scale larger than that of FIGS. 6 and 7.

FIG. 7A diagrammatically illustrates geometric relations of direction oftractor path, direction of path of wheels of wheeled units 31 and 32 andshape of pipe portions 50 and 51 in the stage shown in FIG. 7. FIG. 7Bdiagrammatically illustrates geometric relations of direction of tractorpath, direction of path of wheels of wheeled units 31 and 32 and shapeof pipe portions 50, 51 and 52 in a stageintermediate between thosestages shown in FIGS. 7 and 8.

FIG. 8B diagrammatically illustrates geometric relations of direction oftractor path, direction of wheels of wheeled units 31, 32 and 33, shapeof pipe portions 50, 51, 52 and 53 in a stage intermediate between thosestages shown in FIGS. 8 and 9 at the time of the initiation of aninverse curve in the pipe string 25.

FIG. 9B diagrammatically illustrates geometric relations of direction oftractor path, direction of path of wheels of wheeled units 31, 32 and 33shape of pipe portions 50, 51, 52 and 53 in a state intermediate betweenthose stages shown in FIGS. 9 and 10.

FIG. 12 is an enlarged view of the portion of the apparatus 21 as seenalong the direction of the arrow 12A of FIGS. 11 and 13 to show detailsin that portion of the apparatus.

FIG. 13 is a top oblique view, as seen along the direction of the arrow13A of FIG. 12, of the unit 31, that unit being partly broken away toshow some structural details thereof.

FIG. 14 is a diagrammatic view of the positions of the apparatus 21 on afield 90 during the process of operation of such apparatus.

FIG. 15 is a pictorial representation of the wheeled pipe train assemblyportion 224 as in apparatus 21 during a stage of its operation shown inFIG. 11 as seen along vertical plane or section lA-lA thereof.

FIG. 16 is a pictorial side view representation of a wheeled unit orstation 231 of the pipe train assembly portion 224 as seen alongdirection of arrow 16A of FIG. 15 after a 45 turn counterclockwise fromthe position of parts shown in FIG. 15 of wheel 302.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Generally, the apparatus 21 ofthis invention comprises, in operative combination, a tractor 22 and awheeled pipe train as assembly 24, the wheeled pipe train assembly 24comprises a plurality of wheeled units 23 and a pipe string assembly 25.The group of wheeled units 23 comprises a leading end or front wheelunit 31 and a series oflike trailing units as 32, 33, 34, 35, 36, 37, 38and 39,41, 42, 43 and a trailing end or rear unit as 44 like unit 31.The pipe string subassembly 25 comprises a series of like seriallyconnected pipe units as 51, 52, 53, 54, 55, 56, 57, 58, 59, 61, 62 and63 between, respectively, units 31 and 32, units 32 and 33, 33 and 34,34 and 35, 35 and 36, 36 and 37, 37 and 38, 38 and 39,39 and 40, 40 and41, 41 and 42, 42

and 43 and 43 and 44; and one end pipe unit 64 projecting rearwardly ofthe end unit 44; and another end pipe unit, 50, which extends forwardlyof the front wheeled unit 31. Pipe unit 51 is located between wheelunits 31 and 32 and is firmly connected to pipe unit at its front andunit 52 at its rear and is attached at its front end to unit 31 and atits rear end to unit 32. Another wheeled pipe train 224 is belowdescribed.

Each of the pipe units in the spring 25 are similarly serially connectedto the serially adjacent pipe string unit and similarly attached to thewheel units (or stations) adjacent the end thereof as is unit 51.

In the embodiment 21, the overall length from front end of pipe unit 50to the rear end of pipe unit 64 is 1,300 feet. The pipe units, exceptfront and rear ends, are all of the same length, same outside and insidediameter, same wall thickness and same rigidity and flexibility and samematerial. The wheeled units are only 30 feet apart hence the number ofwheeled units is 44. Each of front pipe units 50 and 51 is one 50 footlength and the rear end unit 64 and its adjacent unit is 50 feet long:accordingly, the wheeled units specifically referred to (32-43) and pipeunits therebetween (51-63) are exemplary of such like wheeled and pipeunits and typical rather than being the complete list of such units.Nevertheless the description of operation and structure of wheeled unitshere described is typical of operation of all such units of apparatus21.

Each wheeled unit of assembly 24 comprises a pair of ground engagingwheels, a wheel supported axle, a bracket supported on the axle and aclamp base supported on the bracket. Each consecutive portion of thepipe string is supported on the consecutive one in the series of suchwheeled units.

Wheeled unit 31 comprises a vertically extending left wheel 101, and anidentical right wheel 102; each wheel comprising a horizontallyextending journal as 134 and 134', the journals each rotatablysupporting one end ofa rigid horizontal axle 103. I

Each of the wheels, as 102 (and 101 and 201 and 202 and 201 and 202') inassembly 24 is alike in size, shape and components and comprises a rigidwheel rim as 133, a plurality of spokes as 132 and a journal 134operatively connected as in wheel 102 (corresponding parts are shown onwheel 101, correspondingly numbered with a as 134'), with cleats as 109on each rim. Another wheel structure is used in pipe train 224.

Each axle as 103 supports a rigid horizontally extending bracket as 104;the bracket 104 has a U-shaped steel section. The axle 103 is firmly yetrotatably attached therein, journals 134 and 134 rotate separately aboutaxle 103 laterally of the end of bracket 104. A rigid clamp base 105,formed of a rigid U-shaped steel channel, about 4 feet long in theparticular embodiment 21 herein described, extends along the length ofthe pipe string, and is attached, as by a plurality of like clamps 106,106' and 106" to the portions of the pipe string adjacent thereto andsupports such pipe string portion.

In the first and last of the wheeled units, 31 and 44, of assembly 24the base, as 105, is pivotally supported on the bracket as 104 by avertically extending cylindrical pivot pin 108 so that the bracket 104and the wheel elements attached thereto may pivot about the verticalaxis passing through the center of that pivot pin.

Each wheeled unit as 32 through 43 comprises a left wheel 201, a rightwheel 202 (like 101 and 102 respectively, and each comprising a journalas 234 and 234 (like 134 and 134) such journals rotatably supporting ahorizontal axle 203 (like 103). The axle 203 supports a bracket 204'(like 104); the bracket 204' (like 104) is a U-shaped rigid steelsection. The axle 203 is firmly yet rotatably attached therein. A clampbase 205' (like is formed of a rigid U-shaped steel channel and isattached as by clamps as 206, 206' and 206" (like 106, 106 and 106") tothe portions of the pipe string adjacent thereto and support such pipestring portion.

Generally, in each of the trailing wheeled units 32 through 43 the basethereof as 205 is firmly fixed to and supported on the bracket thereofas 204 so that such bracket and the elements of such wheeled unitattached thereto may not pivot about a vertical axis passing throughsuch base and such bracket. More particularly, in the trailing wheeledunits as 32 through 43 the bracket element as 204 (referred to as 204'and 204" to indicate the corresponding like units in the assembly otherthan 32) is firmly attached as by welding to the clamp base of suchunit, as 205 (and 205 and 205" respectively), so that no rotation occurstherebetween.

The portions of the pipe string each comprise a relatively flexibleportion of pipe as 51 each provided with a connection joint as 71between adjacent pipe elements 51 and 50 and connection joint 72 betweenelements 52 and 53, a like joint element 73 between pipe elements as 53and 54 and joint element as 74 between elements as 54 and 55. The jointelements comprise a firmly connecting mechanical fitting as 78 and aseal 79. Each seal as 79 provides a watertight seal between adjacentlengths of pipe and is supported by and affixed to the joint, the jointand adjacent one to two feet of pipe is supported by and attached to andheld in place relative to each other by the base as 105 and its clampsas 106,106 and 106" and 106".

laps the area covered by spray from the sprinkler head on the adjacentwheeled unit.

Each of the wheels as 101, 102 and 201, 202 is fixed as to positionalong the length of its axle as 103 and 203 by collar rings as 136centrally and 137 laterally (shown on 103) which are held by lock nutsto the axle,

I 7 yet are movable along the axle. Thereby the position of each of thewheels as 101 and 102 is adjustable along its axle as 103 so that thewheels of assembly 24 move in the parallel furrows as 95 and 96;accordingly, hillocks of the earth as 97 and 97 forming the row crop 7seed bed between such furrows will be straddled by each wheeled unittravelling along the straight parallel A 30 foot pipe that bends 2 /2feet 1% feet from each end if supported at its center) develops a curveof pipe I with a radius of about 90 feet and the lines of travel 125 and126, if about 40 feet apart, requires no more than three stations orwheel units to form an S-curve; a more gradual curve may be formed asshown in FIG. 1 but 40 feet from position 110 to 112 is usual.

In the overall operation of apparatus 21 in a rectangular field as 90having an area of one-fourth section, i.e., 2,640 feet long and 2,640feet wide, (length shown as vertical and width as horizontal in theFIGS. 2 through 11 and 14) having a left side portion 91 and a righthandportion 92 separated by a road 93, after operation as an irrigator, theapparatus 21 moves from the upper left position as shown as 110 in FIGS.2, 11 and 14 to the position shown as 111 in FIGS. 2,11 14, on theright-hand side of the road 93. By the repeated process of movement ofportions of assembly 24 behind tractor 22 (a) in one straight line as125 shown in FIG. 2 followed by (b) motion of sequential portions ofapparatus 2] in an S-shaped or reversed curved path shown in FIGS. 6through 11 and 68, 7A, 7B, 8B, and 9B at an angle to path 125 throughthe zone 11B, in the direction 115 (shown in dotted line in FIGS. 14 and2) followed by (c).motion of increasing sequential portions of apparatus21 along another straight line of travel as 126 displaced from line 125then (d) continuing along that second line of travel (126) as the numberof the wheel units slowly decrease on the left of the road and increaseson the right hand side of road 93. After all portions of the assembly 21are thus brought and spaced apart paths as 125 and 126 to and frompositions as 110, 111, 112 and 113.

to the position shown in position 111 with the tractor 22 at therighthand side of assembly 24 as shown in FIG. 3, the tractor 22 isconnected to the former rear end unit 64 of the assembly 24 as shown inFIG. 3; thereafter the pipe string 25 of the assembly 24 is thenoperatively connected to a water line as 94 and thereafter the adjacentportion of field 90, i.e., the area as 99 is then irrigated. Afterirrigation of the area 99 by the passage of water through unit 24 isstopped the connection to pipe 94 is broken and tractor 22 draws unit 24to the left. The front end of the pipe string portion 50 is firmly yetdetachably attached to the hitch on the back of the tractor 22 duringtravel from position 110 to 111 when tractor 22 draws assembly 24 toposition 111 and the rear end of pipe string portion 64 is firmly yetdetachably attached to hitch 30 on the tractor 22' during travel fromposition 111 to position 112 when assembly 24 is there drawn by tractor22.

The assembly 24 of wheeled unit and pipe string 25 is thus moved in astraight line along path 126 to the lefthand portion 91 of the filed 90to a position as 112 in field 90 through straight line path 116 (shownin dotted lines); the wheeled pipe unit assembly is again connected toan irrigation line, as 94 and water is passed through the pipe stringand sprinklers as 77 to the area 98 adjacent the position 112 of theassembly 24. The irrigating operation of the assembly 24 for area 98 atposition 112 is the same as at position 110 for area 98A. The amount ofarea irrigated at area 98A at shown as position 113. Repetition of thisprocess provides for a full coverage of field 90 with the apparatus 21moving from position 113 to 114 as shown in FIG.

14 and then, as above described, to position 111A and then to position112A and 113A and 114A as hereinabove described for the movement fromone position to position 111 and 112 until the entire rectangular field90 is irrigated. The motion along (a) lines of travel indicated bydotted lines 115 between positions 110 and 111 and motion along lines oftravel indicated as dotted line 116 between positions 111 and 112 hereindescribed in some detail are the same as the motion along (b) lines oftravel 117 between positions 112 and 113 and lines of travel 118 betweenpositions 113 and 114 respectively.

The process of operation of the apparatus 24 ofwhich the overallsequence of irrigating operation has been above described is shown inmore detail in FIGS. 6 through 11. In the operation of the steps shownin FIGS. 2 and 14 for movement from the position 110 to 111 theapparatus 21 is assembled as shown in FIGS. 2

and 14 and 6. With the unit 21 located at a position as 110 on the landportion 91 of the field 90 the tractor 22 draws unit 24 in a straightline parallel to the axis of the pipe string 25 until the station 31reaches a point adjacent to road 93 generally as shown in FIG. 6;tractor 22 is then turned to travel along a path with a direction oftravel along a straight line, 127, which is at a large angle, i.e., 45,to the length of the pipe string 25 to the left (as shown in FIGS. 2 and6) of station 31, and the line, 125, of motion of the wheeled units thento the left (shown in FIGS. 2 and 6) of unit 32.

As shown in FIG. 13, in wheel unit 31 the bracket 104 is pivotallymounted on clamp base 105, hence, as shown, in FIG. 68 wheels 101 and102 of the unit 31 travel in paths parallel to the line of stress 151applied thereto and the bracket 104 of the wheeled unit 31 is supportedon the wheels 101 and 102 in a line perpendicular to the planes of thewheels 101 and 102. The wheels as 101 and 102 thus travel by rollingalong the direction of the chord 151 of each are or curved segment ofpipe as 50 between the pivotal support of the pipe string 25 on unit 31and the tractor attachment to the front end of the pipe string 25. Thepivotally mounted wheels 101 and 102 on the base 105 provide nointerference with each increment of curvature applied to the bendablepipe string by the tractor motion. Accordingly, as shown in FIGS. 6, 6B,7, 7A, 7B, 8, and 8B, which illustrate the progressive stages ofcurvature of the pipe string 25, the bracket 104 of the unit 31 remainsperpendicular to the line of stress applied to the front portion of thepipe string by the tractor 22 rather than having the direction of thatbracket determined by the shape of the portion of the pipe string towhich the station 31 is attached. As shown in FIGS. 6, 68, 7A, 7B and 8on increasing clockwise curvature of the pipe string by the tractor 22in its travel along path 127 a clockwise (as seen from above) curvatureis impressed upon the front portion of the pipe string as desiredbetween two lines of travel 125 and 126 across the zone 11B traversingthe road as 93 between positions 110 and 111.

In the wheeled units as 32-43 wherein the brackets as 204 are mountedfirmly to the base as 205 to which the pipe string is attached and thebracket is fixed perpendicularly to the short segment of pipe to whichsuch base is attached and the wheels as 201 and 202 of such units (32through 43) roll in paths (shown as 153,153',153" in FIGS. 7A, 7B and9B) tangent at their center to the axis of the portion or increment ofcurved pipe to which such bracket as 204 is attached; the cleated wheelsof such units as 32-43 do not permit motion of that increment of pipetransversely to the length of axle of such wheel unit as shown in FIGS.7A, 7B, 8B and 9B (while such motion is permitted in a unit as 31wherein the bracket 104 assumes a position other than perpendicular tothe length of the segment of pipe string to which attached).Accordingly, the first unit 31 (and the last unit 64 when the motion isreversed as shown in FIG. 3) moves along the direction of the chord ofthe curvature applied to the pipe string portion 50 of the pipe string25 between the wheel unit 31 and the tractor 22. Such chordal directionis shown as 151in FIG. 6B, 152 in FIG. 7A, 154 in FIG. 7B, 156 in FIG.8B and 158 in FIG. 8B.

As shown in FIGS. 88, 9 and 98, on increasing counter-clockwisecurvature of the pipe string 25 by the tractor 22 on its travel alongpath 126 a counterclockwise (as seen from above) curvature is impressedupon the front portion of the pipe string 25 as desired between thelines of travel 125 and 126 across the zone 11B of the road as 93between portions 110 and 111 and an ogee or reversed curvature of thepipe string develops between lines of travel 126 and 126 as at 115.

As shown in FIGS. 9 and 9B the chord of the curvature applied to theportion 50 of the pipe string 25 between the wheel unit 31 and thetractor 22 becomes asymptotic to line 126 as tractor 22 moves along theline of position 111.

As shown in FIGS. 6, 6B, 7, 7A, 7B and 8, no bend in the pipe portion 51occurs until, as shown in FIG. 68, after that pipe unit portion has beenmoved to a position rightward (forward) of that at which the wheeledunit 31 was initially located at the position shown as 110. Similarly,pipe section 52 suffers no bend until after it has been moved forward,(right as shown in FIGS. 2 and 6) of the position formerly occupied bywheeled unit 31, that is, until wheeled unit 33 is in the positionformerly occupied by wheeled unit 31 at position 110.

After wheeled unit 31 has moved about one half of the longitudinaldistance which it travels before (as shown in FIG. 8B) travelling in thepath 126 and after another unit 32 has also been displaced to one side(to the bottom of the sheet as shown in FIG. 9) as well as forwardly (tothe right as shown in FIG. 9) the tractor 22 changes the direction ofits path and turns to its left (rightwards as shown in FIGS. 8-11) andcauses the pipe portions 50 and 51 to reverse the direction of clockwisecurvature which had previously been impressed thereupon.

After the tractor 22 has reached the intended line of further travel 126as shown in FIGS. 9, 10 and 11 the wheeled units immediately therebehind(as 31 and 32) are then drawn along to and in the straight line path 126behind that tractor. The continued forward (to the right as shown inFIGS. 98 and 11) motion of the tractor 22 also applies tension along thepipe string 25 and causes the pipe sections 52 and 53 to then assume acurved relationship relative to the other sections of pipe as 54 and 55(similar to that earlier in portions 52 and 53 relative to 54 and 55)while concurrently the tractor 22 travels along a straight line oftravel 126 which is displaced laterally and longitudinally from the lineof travel of the portion of the pipe string 25 that is then locatedleftward (as shown in FIGS. 2 and 6) of the S-shaped portion and suchcontinued movement of the tractor 22 along the line of travel 126results in movement of all of portions of the pipe string 25 in astraight line behind the tractor 22 to position 111.

After the ogee curve is established, as shown in FIGS. 10 and 11, thewheeled units as 33 preserve the ogee curve thus formed in the pipestring 25 while the tractor 22 moves to the right as in FIGS. 10 and 11as the ground engaging members as the cleats as 109 of the wheels as 101and 102 and 201 and 202 and 201' and 202 of each wheeled unit as 31 and32 through 44 of wheel train assembly 24, and rims as 333 and 334 ofeach wheel as 301 and 302 and 501 and 502 and 501' and 502' of eachwheeled unit of the wheel train assembly 224 firmly grip theearth andserve to restrain the pipe to which such wheeled units are attached frommotion parallel to the axles as 203 (or transverse to the length ofpipe) at each of the plurality of points spaced apart along the lengthof the moving pipe at which such wheeled units are attached; thesepoints of attachment with the pipe move with each portion of the pipearrayed in the shape of a curve in a line tangent to that curve withoutfurther action of the operator to maintain such array. The structure ofwheels of pipe train 224 as well as 24 is directed to resisting anyusual thrust thereagainst transverse to the plane of the wheel rim, as133 or 333, such thrust being parallel to the wheel axle at the zone ofengagement of the wheel rim with the ground.

In summary, this invention provides as above described in some detail aprocess of irrigating a rectangular field 90 having two opposinglongitudinally spaced apart sides 88 and 88' and two laterally spacedapart ends 89 and 89' and a water well 140 operatively connected toirrigating pipe lines as 94 and 94' and 94" along the edge of the areairrigated. The lines 94 and 94' could be along the road 93. The processincludes a series of repeated sprinkling maneuvers: the maneuver has twobasic steps, one a motion to one side along the axis or direction of thepipe string 25 of the apparatus 24, and a return step. In the first stepthere is a drawing from one end thereof (the end at which the pipestring portion 50 is located) each of the series of portions of theserially connected pipe string 25 from a first position 110 at one side91 of the field 90; the pipe portions as 31 and 44 extend longitudinallyin said first position from a first point, the end of 64, at the oneside 91 of the field 90 to a second point where the end of unit 50 islocated near the middle of the field. In the first position 110 all ofthe series of pipe portions are in a straight line. The pipe string ismoved along the direction of the length of the first straight lineposition 110 from the first point thereof as end of unit 64 to thesecond point, unit 31 position, past said second point to a secondposition 111 wherein such pipe portion extends longitudinally from athird point (left end of position 111) the position of the end station,as 44, of train 24, which position is near to the road 93 which runsalong the middle of field 90, to a fourth point, the position of unit 31in position 111 near the other'side (88') of the field. In the secondposition the series of pipe string portions 25 are arrayed in a secondstraight line 111 parallel to the line of string 25 in position 110 andbeyond the second point; water is then passed from the well, as 140, andirrigation main lines as 94 and 94' through the pipe string and each ofthe nozzles as 77 on each station as 31 through 44 while the pipe stringis in position 111 to the portion, as 99 of the field 90 adjacent to theassembly 24.

Thereafter the tractor 22 is moved to connect to and draw on pipe unit64 and the pipe string 25 is drawn from the end 64 (opposite to unit 31)from position 111 alongthe direction of length of the second straightline (126) along position 111 to a third position 112 on side 91 of thefield 90 whereat assembly 25 extends again in a (third) straight linefrom a point near the middle of the field to a point near the side 88 ofthe field 90 parallel to its earlier position 110 but displaced towardsthe end 89' of the field 90 a distance that pro vides for a reliable yetsmall overlap in the area covered by the sprinkling action of thenozzles as 77 on the pipe string 25 at positions 110 and 112.

Water from the well and line as 94 is then passed through pipe string 25and its nozzles as 77 to the adjacent portion 98 of the field while pipestring is in position 112.

The process of moving to side 92 to position 113 duplicates the abovedescribed movement from position 110 to position 111 and sprinkling isperformed at positions 113, with position 113 displaced towards the end89 of the field a distance that provides for a reliable yet smalloverlap in the area covered by the sprinkling action of the nozzles as77 in the pipe string 25 at positions 111 and 113.

The process of this invention particularly provides that the drawingfrom position to position 111 includes the steps of:

l. moving the series of portions of pipe string along the length ofposition 110 in a straight line while supporting the portions of pipe as51-63 at each of a plurality of stations 31-43 above the ground at thestations spaced apart along the length of pipe string 25 whilerestraining each of said pipe string portions from movement transverseto its length at each of the points of support on the station 31-43;

moving the series of portions of pipe string 25 between the position ofend station 31 in position 110 and the position of the end station 44 inposition 111 in a curved path, 115, tangent at one, beginning, end totheline of pipe string 25 in position 110 and the other, finish, end ofthe curved path 115 is longitudinally displaced from the first,beginning, end thereof and is tangent to the straight line path 126 atposition 11 1.

The curved path is continuous between its beginning and end. The movingof the series of pipe string portions over the curved path 115 isaccomplished while supporting the portions of curved pipe string at eachof the stations while those stations move with the pipe; movement ofthe. intermediate pipe portions 51-63 along path 115 is in the directionof the tangent to the curved pipe portion supported at the station whilethe station wheels restrain the pipe from motion transverse to thelength of the pipe at each of the station although the stations movewith the pipe along paths 125, 116 and 126. Movement of the series ofportions of pipe string 25 from the left (as shown in FIGS. 2 and 11) tothe right hand portion (as shown in FIGS. 2 and 11) of position 11 1 isperformed while supporting the portions of pipe at each intermediatestation as 31-43 where again the connection of ground wheels, bracketsand axles restrains each of said pipe string portions from movementtransverse to its length at such stations notwithstanding the stressalong the length of pipe string 25 along curve 115. The above process isthen applied to an adjacent field as 90 as shown in FIG. 14 after field90 is traversed as above described.

The process is characterized by that on initial motion of said pipestring 25 along path 115 one end of the pipe string is drawn along apath 127 at an angle (of about 45) to the first straight line of pathand the pipe string 25 is curved between station 31, (the first point atwhich the pipe is supported behind its drawn end 50) and the front ofdrawn end 50. The pipe at station 31, (the first point at which the pipe25 is supported behind the front drawn end of pipe 50) moves along thechords as 151, 152, 154, 156 or 153 of the curve of such curved pipeportion 50 which action serves to establish the S-curve between lines125 and 126. However, the pipe is also curved between its point ofsupport on station 31, (the first point at which the pipe is supportedbehind the first drawn end of pipe 50) and second support point atstation 32 yet the pipe at station 32, as well as 33 and subsequentstation, to 43 at each of such following or intermediate stations thesupport points move along the tangent 153,153 and 153" of the curve ofsuch curved pipe portions while 130 and 130' show line of travel of unit32 along path 115 and so maintains the S-curve and permits a tensileforce along line 126 to move the stations in line 125 in a straight lineparallel to yet displaced from line 126.

The process of this invention also includes that process shown in FIGS.4 and 5 wherein a first tractive drawing means, tractor 22, is attachedto the end of the pipe string at which front end of pipe 50 is locatedin the position 110 and it (22) draws the pipe string 25 from position110 to position 111, and another tractive drawing means, tractor 28,attaches to the end of the pipe string at which pipe unit 64 is; tractor28, so located, is drawn by the pipe string and tractor 22 from the leftend (as shown in FIG. 4) of position 110 to the left end of secondposition 111 while the pipe string moves from position 110 to position111 and tractor 28 draws the pipe string as from the left end (as inFIG. 5) on the position 111 to the left end of the position 112 whilethe tractor 22 is drawn from the right end (as in FIGS. 5 and 3) ofposition 111 to the right end (as shown in FIG. 5) of the third position112 thereby.

The process also includes that the motion of the tractors 22 and 28 becontrolled automatically by a programmed series of commands applied tosuch tractors and initiated and terminated by remote command, as byradio control by conventional means therefor. Such remote control meanson the tractive means to initiate and terminate the action thereof andoperatively connected thereto would be a stop, start, left and rightturn and control as provided by Radio Control Handbook McEntee H.G.;Gernsback Library, Inc. 1961 pages 285 296 (radio controlled tractor)with the radio controlled motor controlling the throttle for a gasolinediesel engine for tractor 22 and a like control for tractor 28.

In a particular embodiment of apparatus 21 as above described the pipe25 is formed of 4 inch o.d. thin walled, i.e., 10 gauge, steel oraluminum metal pipe that bends freely about 3 feet in a 30 foot length.While the spacing between lines of travel 126 and 125 is a matter ofchoice dependent upon the water pressure and distance of spray fromnozzle as 77 with 30 feet between stations as 32 and 33 there is usuallya 30 to 45 foot distance referred between closest postion of position110 and 111 but 60 feet is usual with 45 feet between neighboringpositions as 111 and 112. While the distance, as above described,between wheels as 101 and 102 is adjustable, as 32 inches to 40 inchesbetween rows is usual such is also the usual distance between the wheelsas 201 and 202 of one unit to avoid damage to such row crops, the heightof the wheels as 101, 201, 102 and 202 is usually 30 inches, but couldbe made larger if desired, also the length of the unit 21 is usually1,325 feet.

As the wind frequently changes in the time required for gradualsprinkling to be accomplished over such large areas as treated by theapparatus as 21 (and 27) the adaptability of the above described processusing the apparatus 21 or 27 to vary the distance between positions thatare spaced apart yet parallel as and 112 and between positions as 111and 113 permits that such distance between successive parallel positionscompensates for the effect of varying wind velocity and direction on theground location of the sprays of water from the nozzles as 77 to thefield adjacent the pipe string. The location of position as 113 toanother as 1 1 1 is readily controlled by the operator in manipulationof the apparatus 21 as the relations shown for movement from position110 to 111 may be used in moving from position 111 to position 112 alonga curved path as 115 as well as along the straight path 116 between suchpositions as 111 and 112. Such ready control of relative irrigatingposition provides for even distribution of water by positioning theapparatus so as to avoid excessive overlap of irrigated areas and toavoid failure to cover neighboring areas to be irrigated.

In another embodiment thereof, the apparatus 21 comprises, in operativecombination, tractor 22 and a wheeled pipe train 224. The wheeled pipetrain assembly 224 comprises a plurality of wheeled units 223 and a pipestring assembly 225. Assembly 225 is identical to pipe string assembly25 above described. The wheeled units, as 231 and 232, of pipe trainassembly 224 are identical in structure and function to the wheeledunits as 31 and 32 of pipe train assembly 24 except for the differencein structure of the ground engaging wheels (as 301 and 302 of unit 231).Thus train 224 is the same as 24 except for difference in wheelstructure; for example: wheeled unit 231 comprises a verticallyextending left wheel 301 and an identical right wheel 302; left andright being as shown in FIGS. 1, l2 and 15 which are the same as theleft and right relations of the driver of the tractor as shown in FIGS.2-11, 13 and 14. Each wheel, as 301 (and 302) comprises a horizontallyextending journal as 334 (and 334', respectively, each rotatablysupporting one end ofa rigid horizontal axle 303 (identical to 103).

Wheels 501 and 502 of wheeled unit 232 and wheels 501' and 502 ofwheeled unit 233 of pipe train assembly 224 are identical to each otherand to wheels 301 and 302 of wheeled unit 231 of pipe train assembly224.

Each of the wheels, as 301 (and 302 and 502 and 501 and 502' and 501')in assembly 224 is alike in size, shape and components and comprises arigid rim as 333', a plurality of spokes as 332' and 342' and ajournal334 operatively connected as in wheel 301. As shown in FIGS. 15 and 16,corresponding parts are shown on wheel 302 correspondingly numbered butwithout a prime as 334, corresponding to the showing in FIG. 1 forwheels 101 and 102.

Each axle as 303 (same as axle 103 of pipe train assembly 24) supports arigid horizontal'bracket as 304 (same as 104 of assembly 24) and theremainder of each of the components of each of the wheeled units as 231and 232 of train assembly 224, such as brackets 105, fitting 78standpipe 76 and sprinkler 77 of station 31 are cooperativelystructurally connected and functionally related as above described forwheeled units 31 and 32.

Each rim as 333 is composed of a pair of coaxial equal diameter rigidinner and outer rim rings, 343 and 344, respectively. These rings arespaced apart along the direction of the length of the wheel axle, as303. In the particular preferred illustrated embodiment, each rim ringis formed of one-half inch thick round, corrugated steel concretereenforcement bar as are the spokes as 332. Each of the spokes as 332and 342 of each wheel of assembly 224 is composed of one rigid 1 mainspoke member as 336 and 338 respectively and tached to the outer ring343, while the main spoke member 338 of spoke 342, which spoke 342neighbors to spoke 332 on wheel 302, is firmly attached to and extendsradially outward and centrally from the outer or'distal part of journal334 to and is firmly attached to I the inner or central rim ring 344.Each spoke of wheel 302; e.g., 332 also comprises an auxiliary or branchspoke as 337 which is rigid and firmly attached at one end to andextends radially and diagonally inwards from the main spoke member as336 to and is firmly attached at its other end to the rim ring member(as inner rim ring 344) to which the main spoke member as 336 of thatspoke is not attached. Similarly spoke 342 also comprises an auxiliaryor branch spoke as 339 which is rigid and firmly attached to and extendsradially and diagonally outwards from the main spoke member as 338 toand is firmly attached to the rim ring member, as outer rim ring 343, towhich its main spoke member as 338 is not attached. This spoke structureprovides for a firm and rigid location of the rings as 343 and 344 in aspaced apart relation to each other in a rigid wheel structure. Eachwheel, as 301 and 302, is separately rotatably attached to the axle ofthat wheel and rotatably supports that axle, as 303. Each such wheelstructure, on wheels 501, 502 and 501' and 502' as well as 301 and 302,because of such diagonal extension of the spokes is particularly firmlyresistant to thrusts parallel to the axle of each of such wheels whichthrust is exerted at a plane or zone at which the rim of such wheelcontacts the ground. This diagonal orientation of the rigid wheelspokes, as shown in FIGS. 15 and l, which are pictorial views, meets thethrust parallel to the axle, which is provided at the zone of contact ofthe rim of the wheel when one portion of the wheel train assembly 224 istravelling along a line of travel as 126 while another portion of thesame pipe train assembly 224 is rolling along another path, as 125parallel to 126 but displaced laterally therefrom, as shown in FIG. 15and as also occurs with wheel train assembly 125 as shown in FIGS. 1-11.

This wheel structure of wheel 302, provides a firm ground engagingstructure, as the bottom surface of the rings (as 343 and 344) firmlyengage the ground. Such firm engagement of the rim rings of each wheelof each wheeled unit of assembly 224 with the ground resists thrustparallel to the axle of the wheel of which that rim forms a part whilenot inhibiting the motion of such wheel in a direction transverse to theaxle thereof.

This ground engaging action of such ground engaging structure by wheelsas 301, 302, 501, 502, 501 and 502 and all other wheel units of pipetrain assembly 224 is a distinct improvement over, but qualitatively thesame as provided by the cleats 109 and 109 and 209' on wheels as 102 and101 and 201', respectively of wheel train assembly 24 (as shown in FIGS.1 and 12) and all other wheel units of pipe train assembly 24. Thestructure of wheels as 301 and 302, 501 and 502 provides particularlyrapid clearing of dirt and mud from the ground engaging surfaces thereofduring movement thereof from positions as 110 to 111, and 111 to 112, asshown in FIGS. 2-11, 14 and 1S, and a continuously efficient biting intothe earth thereby to provide a firm engagement between such wheels andthe ground to resist thrust parallel to the length of the axles of suchwheels at the zone of contact between such wheels and the ground. Suchbiting contact and firm engagement for such purpose of such thrustresistance is obtained notwithstanding a concomitant reduction in thearea of bearing surface between the ground and such wheels.

The outside diameter of the wheels 301 and 302 in the particularembodiment shown in FIG. 15 is 30 inches and the space between the ringsforming each rim as 333 is 4 inches.

The width measured parallel to the length of the wheel axle of the rodfrom which the rim is made may vary from inch to 1 inch dependingdirectly on spacing of wheel units and wheel size. The thickness of thecore measured radially from or perpendicular to the length of the wheelaxle is also preferably at least the same size as the rim ring width foradequate rigidity but not much greater, to reduce cost and weight andalso to provide adequate rigidity in view of weight against transversethrust; i.e., in the direction parallel to the direction of length ofthe axle of such wheel. Rounded rod is particularly useful for suchpurpose.

The rigidity of the spokes and spacing of the rim rings is taken care ofby use of the same rod material for spokes and rims.

The center-to-center spacing of rings 343 and 344 is preferably from 3to 6 inches. Such spacing of the rings as 343 and 344 by a distance atleast twice the diameter of the rods from which the rings are made andthe rounded cross sectional shape of the rings provide for readyclearance of the mud that otherwise accumulates on the ground engagingmeans after their location at a zone (as shown as 98A in FIG. 14) nearthe position 110 of the apparatus 21 at which zone the ground of fieldis sprinkled. Such provision for ready clearance of mud improves thebiting or engagement of the rim in the ground (for resistance totransverse thrust as above described) during the motion of the apparatus21 as from position to 111.

The ability of the pipe train assemblies as 24 and 224 according to thisinvention to conform to impressed contours as above described renderssuch apparatus of particular utility in sprinkling narrow and complexshaped areas as in the vicinity of high tension wire towers and also thestar-shaped areas between the circular areas which circular areascovered by conventional circular irrigation apparatuses and whichstarshaped areas are not otherwise covered.

Iclaim:

1. Irrigation pipe train apparatus comprising a plurality ofintermediate wheeled stations and a pair of end wheeled stationsattached to a string of self-supporting a. said intermediate stationeach comprising a pair of ground engaging wheels, a journal at thecenter of each such wheel, an axle supported at each side thereof by thejournals of said wheels, each wheel rotatable about said axle, a rigidrim at the periphery of said wheel, said rim firmly attached to saidjournal, a transverse thrust resistant ground engaging surface on saidrim, a rigid axle bracket, a rigid pipe clamp base, pipe clamps on saidbracket, said bracket supported on said axle, the length of said bracketfixed relative to the length of said axle, said pipe clamps firmlyholding said clamp base to the adjacent portion of said string of pipeand said axle and said clamp base in fixed angular relationship, eachwheel independently rotatable relative to said axle bracket,

. said end stations each comprising a pair of wheels, a journal at thecenter of each end station wheel, an end station axle supported at eachside thereof by the journals of each end station wheel, each end stationwheel rotatable about said end station axle, a rigid end station axlebracket, a rigid end station clamp base, pipe clamps on said end stationbracket, said end station bracket supported on said axle, a rigid rim atthe periphery of each said end station wheel, said rim firmly attachedto said journal, and a ground engaging surface on said rim, the lengthof said end station bracket fixed relative to the length of said endstation axle, said end station pipe clamps firmly holding said endstation clamp base to the adjacent portion of said string of pipe and apivotally movable operating connecting means between said end stationpipe clamp base and said end station axle bracket, and

c. sprinkler means operatively attached to said string of pipe, saidstring of pipe being composed of thinwalled bendable pipe elementsserially connected and said stations are serially connected only by saidstring of pipe, said wheels mounted on said axles for rotation in planeseach of which is parallel to the increment of length of pipe betweensaid axles supporting said pipe along the entire length of said pipestring said wheels.

2. Apparatus as in claim 1 wherein the pipe string of one, first endportion of the pipe train apparatus extends in a straight line and asecond end portion of the pipe string is arranged in another straightline parallel thereto and longitudinally and laterally displacedtherefrom and a third intermediate portion of the pipe string is locatedbetween and connected to said end portions and is in the form of astable ogee.

3. Apparatus as in claim 2 wherein said stations are about 30 feet apartalong the length of said pipe string, said string being about 1,300 feetlong and the flexibility of said pipe in said string is demonstrated bythe resilient bendability of 30 feet ofa length of said pipe of 3 feettransverse to said length when undistorted, and a straight line passingthrough the first straight portion of said pipe string adjacent said oneend portion thereof is located at a transverse distance between 30 and60 feet from a straight line passing through the second end portion ofsaid pipe string. I I

4. Apparatus as in claim 3 comprising tractive means at both ends ofsaid string of pipe each operatively connected to one end thereof.

5. Apparatus as in claim 4 comprising remote control means on saidtractive means to initiate and terminate the action thereof andoperatively connected thereto.

6. Apparatus as in claim 3 wherein the rim of each said wheel on saidintermediate wheeled stations is formed of a plurality of rigid ringsspaced apart from each other along the length of the axle of said wheelby at least twice the width of the rings as measured parallel to thelength of the axle of said wheel, and wherein the diameter and thicknessand width of said rings are approximately equal.

7. Apparatus as in claim 6 wherein said rings are formed of rigid metalof width measured parallel to said length of said axle in range of onehalf to 1 inch and thickness measured radially to length of said axle ofone half to 1 inch with a center-to-center distance therebetween inrange of 3 to 6 inches.

8. Apparatus as in claim 6 wherein each of said rim rings has a roundcross-section.

1. Irrigation pipe train apparatus comprising a plurality ofintermediate wheeled stations and a pair of end wheeled stationsattached to a string of self-supporting pipe, a. said intermediatestation each comprising a pair of ground engaging wheels, a journal atthe center of each such wheel, an axle supported at each side thereof bythe journals of said wheels, each wheel rotatable about said axle, arigid rim at the periphery of said wheel, said rim firmly attached tosaid journal, a transverse thrust resistant ground engaging surface onsaid rim, a rigid axle bracket, a rigid pipe clamp base, pipe clamps onsaid bracket, said bracket supported on said axle, the length of saidbracket fixed relative to the length of said axle, said pipe clampsfirmly holding said clamp base to the adjacent portion of said string ofpipe and said axle and said clamp base in fixed angular relationship,each wheel independently rotatable relative to said axle bracket, b.said end stations each comprising a pair of wheels, a journal at thecenter of each end station wheel, an end station axle supported at eachside thereof by the journals of each end station wheel, each end stationwheel rotatable about said end station axle, a rigid end station axlebracket, a rigid end station clamp base, pipe clamps on said end stationbracket, said end station bracket supported on said axle, a rigid rim atthe periphery of each said end station wheel, said rim firmly attachedto said journal, and a ground engaging surface on said rim, the lengthof said end station bracket fixed relative to the length of said endstation axle, said end station pipe clamps firmly holding said endstation clamp base to the adjacent portion of said string of pipe and apivotally movable operating connecting means between said end stationpipe clamp base and said end station axle bracket, and c. sprinklermeans operatively attached to said string of pipe, said string of pipebeing composed of thin-walled bendable pipe elements serially connectedand said stations are serially connected only by said string of pipe,said wheels mounted on said axles for rotation in planes each of whichis parallel to the increment of length of pipe between said axlessupporting said pipe along the entire length of said pipe string saidwheels.
 2. Apparatus as in claim 1 wherein the pipe string of one, firstend portion of the pipe train apparatus extends in a straight line and asecond end portion of the pipe string is arranged in another straightline parallel thereto and longitudinally and laterally displacedtherefrom and a third intermediate portion of the pipe string is locatedbetween and connected to said end portions and is in the form of astable ogee.
 3. Apparatus as in claim 2 wherein said stations are about30 feet apart along the length of said pipe string, said string beingabout 1,300 feet long and the flexibility of said pipe in said string isdemonstrated by the resilient bendability of 30 feet of a length of saidpipe of 3 feet transverse to said length when undistorted, and astraight line passing through the first straight portion of said pipestring adjacent said one end portion thereof is located at a transversedistance between 30 and 60 feet from a straight line passing through thesecond end portion of said pipe string.
 4. Apparatus as in claim 3comprising tractive means at both ends of said string of pipe eachoperatively connected to one end thereof.
 5. Apparatus as in claim 4comprising remote control means on said tractive means to initiate andterminate the action thereof and operatively connected thereto. 6.Apparatus as in claim 3 wherein the rim of each said wheel on saidintermediate wheeled stations is formed of a plurality of rigid ringsspaced apart from each other along the length of the axle of said wheelby at least twice the width of the rings as measured parallel to thelength of the axle of said wheel, and wherein the diameter and thicknessand width of said rings are approximately equal.
 7. Apparatus as inclaim 6 wherein said rings are formed of rigid metal of width measuredparallel to said length of said axle in range of one half to 1 inch andthickness measured radially to length of said axle of one half to 1 inchwith a center-to-center distance therebetween in range of 3 to 6 inches.8. Apparatus as in claim 6 wherein each of said rim rings has a roundcross-section.